Food Security
10 October 2019

Food Security and Land Use in the 21st Century: The Return of Malthus?

The coming century raises many important problems regarding population, food requirements and land use. In many ways, the issue at hand reminds us of economist Thomas Malthus’s bleak predictions regarding the interlinkages between population growth and resource constraints. Nevertheless, the problems of the coming century are likely to be very different from those that the Reverend Malthus foresaw.  

The global population is expected to increase to about 11 billion by the year 2100. The earth has never before experienced population pressures of this nature. The amount of land in use for agricultural production reached about 1.3 billion hectares in 1960, and has since expanded to close to 1.6 billion hectares, with most analysts suggesting that the limit of arable land available is about 2 billion hectares.

Of course, placing all of the globally available arable land in the service of agricultural production is not desirable. Alternative land uses are required to sustain the planet. Biodiversity preservation is dependent upon land use allocations, as habitat conversion is one of the primary drivers of species loss.

Also, carbon sequestration depends upon the retention of existing forests and their expansion. In the coming century, with the onset of multiple global problems such as climate change, meeting food requirements from reduced land allocations proves crucial.

In line with population changes, the primary locations for new agricultural lands are situated in developing countries, most importantly in sub-Saharan Africa. Conversely, in developed countries, the rate of agricultural land use growth has already turned negative.  

The reason for the lower land-use rates in the developed world is partly due to slowing population growth. The more important contribution to this trend, however, has been the impact of research and development (R&D) in the agricultural sector, which led to exponential productivity rates over the past half-century. This has been true to the extent that in many developed countries, overall production has multiplied while land use has gone into decline.

In order to ascertain the extent to which this phenomenon is able to address the issue of food security, I, along with Ozgun Haznedar, Bruno Lanz and Pedro Naso, have estimated the global agricultural production function for the period 1960–2010, and then extrapolated the results, applying them to a global context for the remainder of this century. 

Our results are striking, in that they indicate that vast amounts of global land may be released from agricultural production, with relatively minor consequences for overall food production. They demonstrate the relatively minor welfare losses that come from placing constraints on land use in agriculture (i.e. releasing land for other uses, such as biodiversity and climate change). In essence, this shows that land is no longer the resource constraint that it once represented and that it is feasible to substitute R&D for land use to a large extent.

In the 21st century, declining population growth rates are, paradoxically, accompanied by increasing levels of population. The combination of high population levels and low growth rates will effectively “invert” the population pyramid in coming decades. This implies that global dependency rates (those over 70 years of age) are expected to approach 30% – up from 7% over the past half century – with much higher rates in individual developed countries.

An inverted population pyramid implies a very large older population, unlikely to contribute to the R&D sector. This means that the source of the solutions to Malthusian dilemmas since the 18th century – the application of younger pools of talent to this particular form of problem – are significantly diminished. The Malthusian dilemma of the 21st century is therefore different because we are facing constraints of both natural and human capital, in the context of increasing food requirements.

Is there a solution to this problem of increasingly constrained resources (human and natural) in the context of increasing global populations? If there is, it lies in the immediate investment of global funds into the human capital of developing nations. It is only in these regions of the world that both arable lands and population resources will continue to increase in certain parts, principally sub-Saharan Africa.

The solution to the problems of the 21st century probably lies in replicating the experience of the developed world in the developing. If the developed world has been successful at substituting human capital (and resulting R&D) for natural capital in the recent past, then this is likely to be possible in the developing as well. 

The nature of these investments may take many shapes: investments in developing world agricultural production, investments in the human capital of the developing world (by, perhaps, sending more individuals from that part of the world to work or learn in other parts), investments in the technologies and extension agencies of the developing world, and investments in the institutions of higher learning in the developing world.

This is of course a very partial list of potential solutions, but at their core lies the need to integrate the resources of developing and developed parts of the world. The human capital in developing regions needs to be a crucial part of the solution to the food security problems of the 21st century.

Professor Swanson will participate in a panel discussion on "The Future of Food Security", to be held Tuesday, 12 November 2019. 

This article will be published in the next edition of Globe and in Global Challenges (no. 6 2019), the Graduate Institute's series of research dossiers. 

Keywords: international economics